A problem arising in the operation of conventional gasoline engines resides in incomplete combustion, which may produce toxic combustion residues, which enter the ambient air and pollute the regions near streets and roads. The most highly toxic compounds which are emitted are carbon monoxide (CO), hydrocarbons (C.sub.m H.sub.n), nitrogen oxides (N.sub.x O.sub.y) and lead compounds (Pb(C.sub.2 H.sub.5).sub.4 and PB(CH.sub.3).sub.4), which are added to the gasoline as antiknock agents. The average quantities in which the above-mentioned components are emitted in case of an incomplete combustion of 100 liters of gasoline amount to about 10 to 30 kg CO, 2 to 4.8 kg C.sub.m H.sub.n and 0.2 to 1.5 kg N.sub.x O.sub.y. Only CO.sub.2, H.sub.2 O and N are emitted when pure gasoline (without antiknock agents) is completely burnt. At the present time, regulations in effect in the United States (California Test, abbreviated as CT, and Federal Test Procedure, abbreviated as FTP) require a stagewise decrease of the noxious components of the exhaust gas or of the additives to gasoline. For this reason great efforts are being made by the automobile industry to fulfil these requirements. In carburetor motors, these efforts are made in the direction of improved carburetors. Inherently better results are produced with engines operating with direct fuel injection but still do not meet the requirements of CT and FTP. A so-called "catalytic converter" has also been added in order to improve the oxidation. The present effective efficiency of internal combustion motors amounts to between 23 and 28% and must be regarded as rather low.
For this reason it is an object of the invention to provide a novel four-stroke-cycle internal combustion engine which is friendly to the environment and delivers no deleterious exhaust gases in any speed range.
The novel four-stroke-cycle internal combustion engine is to be useful for various fuels, such as kerosine, alcohol, benzene and particularly for unleaded gasoline.
Besides, the novel four-stroke-cycle internal combustion engine should have a higher efficiency than conventional engines of that kind.